Copper base alloy



Patented Apr. 12, 1949 GOPRER BZSSE ALLOY Vladimir "A: Grodsky, Washington, D. G.

No l)nawing. eApplicationDecember 4, 1944,

SeriaLNo. 566,630

'(Granted underthm act of March- 3, 1883, as amended Ap11il-30, 1928;370 OQG. 757) team.

This invention :relates to copper base alloys and :has particular relation to alloys are adopted for use as a casting metal, :a-s i-a bearlng metal or as a weldingni'etal.

A principal object nf the invention is to *provide a new andzimproved copper base alloy which has good oastingpropertiesaandhas among other advantageous characteristics raz lrighresistance to corrosion, :a low zporosity and a correspon ding high density. 1

Another object ofRtheei-nventiohiistoiprcyide a copper base alloy which is adapted; for usea s a high pressure roasting alloy, ibear'ing :ralloy rand welding alloy.

A further :object tofthe invention is :to provide; a copper base alloywhichzmaysbe cast and maybe welded :either electrically orby za gas weld with a Welding rod composed of the same alloyas-the casting.

A still further object is tomrovide 'a-zcopper base alloy having improved "physical properties as a castmetalrsuch asgood machineabil-ity,.high resistance to shock, low meltineitemperature, low casting temperature and short melting time.

Another object of "bl'lBiiI'lMBfifilQIl'iS to provide a copper base alloy'which has improved :physical properties for"welding:purposesasuch as smooth, free flow during welding, the ability :tobe meld!!- trically welded as well as gas welded, and=t=he ability to weld --satisfactoriiy with a minimum number of fillets required for the weldment thereby eliminating thefneedfor chipping and rewelding.

Still another object is to provide .a copper base alloy which is economical to manufacture, due in part to the'large-percen-tage oflead contained therein and the absence of any appreciable amount of tin, or tin and zinc.

Still another object is to provide a copperbase alloy containing no appreciable percentage of-tin, which is suitable'for use as a bearing bronzeea-stingand the physical propertiesof which generally conform to high grade bearing bronze'such as specified in Navy Department Specification 46B22e, issued February 1, 194$.

These and other objects of theinvention wtll be better understood from the following description.

The majority of copperhasezalloys form solid solutions in which theamount ef -components is close to the saturation point, and the copper base alloys of the 'presentinvention belong to this group. Present'zbronze Valleys comprisesea sentially a copper base and tin, or tin and zinc. Phosphorus has heretofore been used in a small amount in the preparation of bronze alloys as-a deoxidizingagent, with a negligible trace thereof remaining in the final alloy product. Theailoy of the present invention'i-s -.di-stinguish-ed-from prior copper base alloys.-in--one respect inthat it contains a substantial phosphorus content in the final alloy product. wContrary to all expectations, it has been found that a strong copperlead bronze alloy, which is well suited for-high pressure castings and bearings, can-be produced by the inclusion of phosphorus in a proportion which makes it a substantial constituent-of the final alloy.

In accordance"with' thepresentinvention, the desirable physical properties of known copper base alloys 7 are, markedly improved bycpreparing afinalproduct alloy containing approximately 5 to 20% lead, 2 /2 to 10% phosphorus, 0.5% .to 3% of a lead dispersing agent such as vnicks-:1 and the balance copper, thefa'm'ount of impurities present being insufficient to'al'ter the essential properties of 'thealloy. Within the above'ranges it has been found that for general I purposes among the loptimumproportions are approximately'8 to12% lead, 3't0 4% phosphorus,0i'7'5% to 1.5% lead dispersing agent and the remainder copper.

Small amounts of other components, such as modifiers, maybe added to mixes of the above basic components taken as'100% in ord'er'to improve particular properties of the present alloy. Thus,the'inclusion'of'from0;2'% to 0.5% antimony refines the structure; affords a smaller and more uniform grain and also increases the tensile strength and'lductillity of the present alloy.

Antimony alsoacts'as a lead disperser and when used as such, in 'place .of nickel-or other disperser, its total amount should preferably not be substantially in excess of 3% in orderto avoid brittleness.

as lithium i has a high aifinity for practically all elements which occur as non-metallic impurities.

A small amount of tel-lurium,up to 0.1%, serves :iIn producing the irieW :alloy, the phosphorus;

content may be conveniently introduced as a part of a, conventional phosphor-copper alloy which The addition of up to 0.03% lithium: acts as an excellent scavenging agentin-asmuch and having a total area of 4.2 in.

is a commercially available product usually comprising from about to phosphorus and 85% to 90% copper. The copper, disperser and part (for example 75%), of the above-mentioned phosphor-copper alloy are melted in a crucible at high furnace temperature such as 3000 F. When the charge is melted, the rest of the phosphor-copper alloy is added, thereby resulting in the removal of oxides which may have been formed. When the temperature reaches about 1800" F., the lead is added and the whole melt is stirred to obtain an intimate intermixture. Melting is preferably accomplished as quickly as possible in an oxidizing atmosphere to prevent the absorption of gases. The molten charge, after skimming, is poured into molds or injected as soon as it reaches the required pouring temperature, or, as is preferred, the molten charge is cast into stock pigs which are remelted for use. If desired, the phosphorus may be introduced into the molten copper, together with the disperser, and the lead may be added to the molten mass.

The following are examples of copper base al- The above alloy was cast into a number of test ingots which exhibited the following average physical properties: tensile strength, 38,000 p. s. 1.; yield strength (.01 inch extension in 2 inches under load, 15,000 p. s. i.; elongation in 2 inches, 9.2%; reduction in area, 8.1%; modulus of elasticity (tension), approximately 10,000,000 p. s. i.

The above alloy was also cast in the form of optical instrument bodies, i. e., rangefinder tubes and gun turret telescopes which were successfully subjected to a 2000 lb. shock test. This shock test consisted in applying three horizontal and three vertical strokes of 2000 lbs. each to the casting.

The same cast alloy was also subjected to a synthetic sea water spray test for 70 hours in the form of discs 1.5 in. diameter, in. thickness Steel discs of similar dimensions, included for purposes of comparison, were snugly sandwiched on both sides of the alloy discs. The alloy discs made in accordance with the present invention exhibited a corrosion loss of 1.6 mgr./in. as compared to a corrosion loss of 7.0 mgr./in. for the steel discs.

EXAMPLE 2 Components: Percent Lead 8.65 Phosphorus 3.15 Nickel 1.12 Copper Balance The above alloy was cast in the form of bearing bronze castings which were tested for their physical properties in accordance with Navy Department Specification 46B22e issued Feb. 1,

4 1944, and the bearing castings were found to meet the specification with respect to all physical requirements.

. EXAMPLE 3 Components Percent Lead 14.95 Phosphorus 5.95 Nickel 1.0 Copper 78.1

The above alloy was formed into standard electric welding rods of inch diameter which exhibited a Rockwell B hardness of before welding and 34 after welding. The weldment had a tensile strength of 39,000 lbs/in. and an elongation between 0.5 and 1.0%.

The welding rods were exposed to a synthetic sea water corrosion test for three months after which they exhibited a loss in weight of only 0.376%.

For use as a welding rod it has been found! preferable to keep the phosphorus content at not less than 5%. Thus, a welding rod alloyg which has been found advantageous is constituted substantially of approximately 6 to 12% lead,'; 5 to 7% phosphorus, 1 to 2% disperser (preferably nickel), and the remainder copper, the amount of impurities and modifying agents present being insufiicient to alter the essential properties of the alloy.

The alloys of the present invention have a low melting point, around 1400 F., thereby resulting in a saving of fuel and melting time and minimizing the opportunit for the absorption of injurious gases. Another advantageous feature is the low pouring temperature of the present alloys, which is in the neighborhood of 1700 to 1800" F.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

A copper base alloy consisting of essentially 8 to 12% lead, 3 to 4% phosphorus, 0.75 to 1.5% nickel as a dispersing agent for the lead and the balance copper, except for minute proportions of impurities.

VLADIMIR. A. GRODSKY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 217,946 Jackson July 29, 1879 646,118 Clamer Mar. 26, 1900 646,119 Clamer Mar. 27, 1900 1,286,921 Berry Dec. 10, 1918 1,652,107 Eschholz Dec. 6, 1927 2,018,417 Peyinghaus Oct. 22, 1935 2,040,055 Lytle May 5, 1936 2,079,481 Bennett May 4, 1937 2,229,117 Ness Jan. 21, 1941 FOREIGN PATENTS Number Country Date 5,218 Great Britain Dec. 13, 1880 OTHER REFERENCES Metals and Alloys, Dec. 1942, page 1074. 

